In another incident of ceasefire violation, a Border Security Force trooper was injured Wednesday morning in unprovoked firing by Pakistani Rangers in Jammu and Kashmir's Ranbirsingh Pora sector, officials said. The firing started around 6.30 a.m. and lasted for more than 90 minutes. One BSF trooper was injured, a BSF source said.BSF retaliated with equal ferocity to this "unprovoked firing from across (the border)", he added. The incident of firing from across the international border in Ranbirsingh Pora sector, 30 km west of Jammu, was described as a violation of the ceasefire. "It is now becoming a trend from Pakistani side, they have started violating ceasefire every now and then," the source said.Pakistan had opened fire in Chak Phagwari post in Pargwal sector along the border Tuesday; before that on July 16, Pakistani troops opened heavy fire at five positions along the Line of Control and at another place from across the International Border in Jammu and Kashmir.